look for “convertRGB”. there isn’t much going on, and what is going on, is conditional on a few things that might not hold true in your case.
you’ll note the latest change is 8 days ago and is related to this feature.
and there are a bunch of open issues mentioning the cap prop flag.
that means you can’t expect this to work yet. if you have trouble, consider adding your voice to an appropriate issue on github, or create one if you found a new problem.